The present invention relates to component mounting apparatus and method for automatically mounting a variety of components such as electronic components onto a printed circuit board or the like, and a component mounting equipment including the apparatuses.
Generally, in an electronic component mounting apparatus, a number of component supply means are mounted in parallel to one another on a component supply table. In a component mounting stage, the component supply means are successively positioned in a specified component supply position according to a sequence of mounting components while moving the component supply table in a direction in which the component supply means are arranged in parallel. Then, each of the components at the component supply means is taken out by suction by a mounting head section, and the components are transferred to a circuit board positioned in the circuit board positioning section to be subjected to a component mounting process.
This type of conventional component mounting apparatus will be described with reference to FIG. 6 showing a perspective view of it and FIG. 7 showing a schematic plan view of it. In FIG. 6, at the front of an apparatus body 1 is provided a board positioning section 4 for positioning a circuit board P supplied from a board supply means 2 in a mounting position, and the circuit board P mounted with the required components in the board positioning section 4 is discharged by a board discharge means 3. On the other hand, at the rear of the apparatus body 1 is provided a component supply section 7, and a rotary type mounting head section 8 is provided between the component supply section 7 and the aforementioned board positioning section 4 as shown in FIG. 7.
In the component supply section 7 two component supply tables 10 and 11 are laterally movably provided independently of each other on a guide rail 9. The component supply tables 10 and 11 are mounted with a number of component supply means 12 arranged in parallel to one another in a direction in which the component supply tables 10 and 11 move. There is illustrated generally a so-called parts cassette as the component supply means 12, and it will be simply described below. That is, electronic components of an identical type are stored and arranged at regular intervals on a carrier tape while being wound around a reel 13 as covered with a cover tape. By drawing out the carrier tape from the reel 13 to feed it at a pitch equal to the storage intervals of the components and taking up the cover tape, the electronic component located at the leading end is positioned in a component supply position A opposite to a component suction head 14 of the mounting head section 8.
Furthermore, as shown in FIG. 7, the mounting head section 8 is constructed by providing a plurality of component suction heads 14 at regular angular intervals on an identical circle of a rotary table (not shown) provided rotatably around a vertical axis. Each component suction head 14 is designed to suck a component by vacuum suction means. Upon intermittently rotating the rotary table, it is stopped in steps in the component supply position A and a component mounting position B in order to concurrently perform receiving of each component from the component supply means 12 and mounting of each component onto the circuit board P. While one component supply table 10 is supplying components, the other component supply table 11 that is retreating in a standby position performs changing of component supply means 12 and replenishing of components thereby achieving preparation so that the component mounting apparatus can be operated continuously.
In recent years, there has been a growing trend in that the types of circuit boards P to be manufactured and the types of components to be mounted on the circuit boards P are increasing. In order to cope with the above, one solution to be considered is to increase the number of component supply means 12 to be mounted on the component supply tables 10 and 11. However, in such a case, the component supply tables 10 and 11 are to be elongated sidewise in order to increase the number of component supply means 12. Consequently, the length of the entire component supply section 7 becomes very long, and this leads to a degraded space utilization efficiency, reducing the productivity per floor area.
A more important issue is that the component supply tables 10 and 11 are fed at a pitch in accordance with taking out the components by the mounting head section 8, and therefore, the following inconvenience occurs. That is, when the component supply tables 10 and 11 increase in weight due to the increase of their lengths, not only is greater drive power required to move the component supply tables 10 and 11 but also the inertial force of the component supply tables 10 and 11 increases. Therefore, vibration in feeding the component supply tables 10 and 11 at a pitch significantly increases. Consequently, it is impossible to increase the component supply rate, or the component mounting operation speed.